I can only comment on what I have...
My Thor Impact Rig SE is far more comfortable than any injuries from bouncing off of rocks with "street" riding gear on with built in armor that can shift out of place off road. Look at my high speed dirt/rocks crash video on my website, the Impact Rig is crash tested and protected me from serious injury whereas I don't believe any standard jacket with armor in it would have.
I do wear a gerbings jacket under it in cold weather sometimes, works great, with it that close to your skin only low temp heated is needed, so it's possible. YYMV

I will usually take off the armor when sitting at lunch time, but have no issues with riding day in and day out with it on and leave it on all the times I'm not stopped at a restaurant, and yes just a jersey is great for hot weather, assuming you're not on pavement where you'll want to have your outer jacket on for abrasion protection.

Got a wave pro pressure suit and it is a bit bulky, though fortunately don't notice it that much on the bike (guess because designed for that). Still think some people would feel it was a bit much, other suits are lighter. You do feel safe in it though.

Not tried heated gear under, does sound a bit thight, and wouldn't wear it over. I wear heated vest at low temps, well under freezing point, but then under jacket with armour and separate back and chest protectors. And 3 feets of snow

Don't mind wearing pressure suit, though guess more comfortable with a jacket if not too hot, then pressure suit with cross jersey is fine, those cross shirts take some beating (not on tarmac though). But pressure suit is safest.

I think for dirt oriented touring the pressure suit layer combo is more comfortable, I use a heated vest under mine on a regular basis.

I wear various ADV or leather armored jackets for around home commuting but for multiday trips the pressure suit and layers works better.

I took this picture after several days of riding and sleeping in temps over 100, two days later I was in the northern states riding in the frost, the ogio vest hanging beside my armor has the heated vest, rain shell and a down jacket in the pocket.

I was considering a pressure suit + jacket for daily use....I can say I tried on a few pressure suits, and the suits themselves werent uncomfy, but some of them were an absolute bitch to pull a jacket over the top of. I think it was a fox one, I couldnt get the jacket off by myself because of the way it hooked the chest protector.

When on everything seemed great. It was the going on and off part that sucked.

My 661 pressure suit saved my ass twice in the last two years. Unfortunately the last time they had to cut it off so now no choice...getting a new one. Been thinking of the Leatt model which obviously works well with my neck brace. The main advantage is it stays in place when you crash.

I wear a Thor Impact Rig SE with a Klim Traverse jacket. It works fine and I don't notice the pressure suit while riding. While the (2012) Traverse is large enough it has an odd cut to it, it doesn't quite lay on the shoulders/armpit area very well. I don't notice it during riding, only when putting the jacket on.

When warm you can put a jersey over it or just wear the rig over your t-shirt.

I don't wear it daily though.

If I needed something daily, I'd get an armored jacket out of convenience. Donning the rig & taking it off certainly isn't as easy as a jacket. The suits are made to hug your body so the armor doesn't slide around on you. Since it is form fitting you have to tug at the bits & pieces to get them in the correct position.

If you've got a bit of a belly, it'll want to stick out the bottom of the rig or cause it to ride up a little bit.

I wear a Cosmo. Comfortwise, it's fine, I don't even notice it UNLESS it's hot out. Then, whenever you stop or ride in slow, technical terrain, the bastard will burn you up. But I like it for fast single track and connecting trails. I don't wear the waist/kidney belt portion. There's no protection offered there anyway.

I wear an older TLD Descender (cloth mesh version of the leather Speed Jacket) and it is super comfy and cool with a jersey or non armor enduro jacket. Mobility is good too, originally got it for super-moto and it's very tough, only minor scuffs on the armor even after shreading a jersey or two Also has an adjustable kidney belt built in. I believe both are discontinued, but there some places on line that still have some available new, and of course you can find used ones around.

I just spend the day riding in my new thor impact rig se. It fits amazingly comfortable and I like how things will actually be in place if I crash. Only time will tell how durable it is but it wasn't expensive so I figure if I get a year out of it I'll be pleased.